1. Field of the Invention
The present invention relates to a recording substrate treatment apparatus, in particular a recording substrate treatment apparatus for a printer or copier. For example, the recording substrate treatment apparatus comprises at least one of a drying device for drying a recording substrate and a fixing device for fixing a printing substance on a recording substrate. For example, the fixing device may be or comprise a fuser. The present invention further relates to a printer or printing system comprising a recording substrate treatment apparatus.
2. Description of Background Art
In the field of copying and printing, it is known to dry or fix prints on a recording substrate. For example, a fuser is known for fixing toner powder to a printing substrate, such as a sheet of paper. For example, a fuser comprises a radiant heat lamp, which may be arranged to heat a printing substrate support roller for heating and bonding the toner to the paper.
Fixation of a printing substance to a recording substrate usually involves heating the recording substrate comprising the printing substance and evaporating a solvent and/or water stemming from the printing substance (e.g. an ink).
In inkjet printing, in particular water based inkjet printing on flexible absorbing recording substrates (such as plain paper and machine or offset coated paper), deformation of the recording substrate may occur upon drying of the recording substrate and/or fixation of the printed image on the recording substrate. Such deformation may, at least in part, be prevented by rigidly fixing a recording substrate during drying and fixation. For example, a sheet of a recording substrate may be rigidly fixed on a transportation mechanism by a vacuum force induced by a suction device.
In the published international patent application WO 2013/131751 A1, a recording substrate treatment apparatus comprises a transporting mechanism for transporting a sheet of a recording substrate; a suction device to provide a vacuum force at an outer surface of the transporting mechanism arranged for holding down a sheet of a recording substrate; a heating device for directly heating the recording substrate; and a blowing device for providing a flow of a gaseous medium at the outer surface of the transporting mechanism, wherein in operation the blowing device receives the gaseous medium from the suction device.
The disclosed recording substrate treatment apparatus comprises an in-box (26) to which, in operation, all air-flows extracted from the drying and fixation device 20 are fed. The in-box (26) is in fluid connection with an out-box (28) from which all air-flows to different functional parts (e.g. impingement device(s), heater cooling) in the drying and fixation device (20) are fed. This arrangement has been designed to balance air-flows in the drying and fixation device (20) to prevent pressure fluctuations in the interior space of the drying and fixation device (20). The arrangement also enables venting of a fraction of the total air via an exit of the in-box (26) and taking in fresh air in the out-box (28) to compensate said fraction, such that the (relative) humidity inside the drying and fixation device (20) can be controlled.
It is a disadvantage of the recording substrate treatment apparatus disclosed in the background art that, due to the dynamics of the different air flows, the disclosed configuration is an ill balanced system.
It is another disadvantage of the recording substrate treatment apparatus disclosed in the background art that each air-flow requires a separate suction or blowing device (fan), at least for each different function, which may result in a complex and expensive configuration, requiring a complex control configuration.
It is another disadvantage of the recording substrate treatment apparatus disclosed in the background art that all incoming air-flows are mixed and redistributed, which does not enable the most energy efficient way of operation, e.g. the incoming air-flow from the air suction drum to hold down the print substrates may be (slightly) cooled due to adiabatic processes.